In article <336DCBDB.5570 at ibsm.cnrs-mrs.fr>, Athel <athel at IR2CBM.CNRS-
MRS.FR> writes
>>Can we stop saying "below saturation" when we mean "far below
>saturation"? I know Henrik started it (with his "straight chain of
>unsaturated enzymes"), but even the Pope can have an off day. When
>enzymologists say "unsaturated" they mean v less than about 90% of Vmax.
>When you guys say "unsaturated" you mean v less than about 1% of Vmax,
>since otherwise the approximations don't approximate. This seems an
>intolerably large gap to me, and isn't even justified by everyday
>language -- people in ordinary life don't say "unsaturated" when they
>mean "nowhere near saturated", if indeed they use the word at all (other
>than in talking about unsaturated fats, where they have no idea what it
>means).
>>Athel
>Yes you're right, I just did a quick calculation and even to get 0.9 of
an elasticity for a simple irreversible step the substrate concentration
has to be about 10 times less than the Km. Indeed when I referred to
below saturation it has clearly to be well below saturation which may or
may not be a useful observation when considering real systems.
Herbert
--
Herbert M Sauro
email: HSauro at fssc.demon.co.uk
Telephone: 01974 282428
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